Patent GB-538758-A (GB)
Title: Improvements in and relating to hydrokinetic torque transmitting devices
IPC: F16H61/62
Filed: 1940-02-06
Abstract: 538,758. Hydraulic transmission of power. HEPPNER, F. A. M. Feb. 6, 1940, Nos. 2312 and 4883. [Class 69 (ii)] [Also in Group XXXIV] In a hydraulic torque transmitting device the pump 1 and turbine 2 are provided with channels 3, 4 arranged in such a way that at the smaller radius there are a plurality of separate rows of channels 5, 6 ; 7, 8, one beside the other with the channels of one row staggered with respect to those of the next, said channels being left completely separate from each other and interlaced into a smaller number of rows at the larger radius of the pump and turbine. As shown in Fig. 1, there are two inner rows and one outer row, and the pump and turbine wheels may be formed of pressed sheet metal or of pressed synthetic resin preferably reinforced by wire gauze. A reaction wheel 23, Fig. 3, may be located at the radically innermost part of the circuit between the turbine wheel 2 and the pump wheel 1 and fitted with as many rows of channels 13, 14 as the turbine wheel has at its outlet. This reaction wheel 23 may be arranged to act in conjunction with an epicyclic gear 28, 29, 31 on the output shaft 30 of a motor to act as a reversing gear. The wheel 23 is on a hollow shaft 24 fitted with a free-wheel device 26 the other part of which carries a brake drum 27. When this brake is on the shaft 24 and wheel 23 can rotate only in the direction of the drive and the device acts as a coupling and not as a converter. When a brake 32 is applied to the outer member of the epicyclic sun-and-planet gear the shaft 30 is driven in a direction reverse to that of the wheel 23. The bands 27, 32 of the brake drums are operated by means shown in Fig. 5 which releases one band as the other is applied. The bands are connected to an eccentric pin 34 on a shaft 33 which is rocked into either of its extreme positions by a lever 37 fitted with a spring-pressed roller 39 which acts upon cam surfaces 35, 36 formed of two arcshaped eccentric members of equal radius which are substantially concentric to the pivot 38 of the lever when the roller 39 engages the end of the cam. The shaft 33 passes through a position in which neither band is applied and a spring- catch 42 may hold the bands in this position. The shaft 24 is fitted with a cooling fan 25, Fig. 3, and fluid can pass into the working chamber from a reservoir 19. Valves 21, 22 which open centrifugally are provided to give pressure equalization with the outer atmosphere and to guide return leakage from the working chamber to the reservoir. In a modification, the reaction member is mounted so as to be capable of sliding axially from a position in which it engages frictionally the turbine member to a position in which it is coupled to an epicyclic gearing which can be brought into action to effect the reverse drive. The turbine channels are curved in one direction only, and the rows of smaller radius are set at a steeper angle than the more remote rows. The partition walls between the channels at the inlets to the turbine are cut away substantially down to a cylindrical surface having its generator lying in the outer boundary of the arc of the circuit.